The gang supplied the drugs to organised crime groups across the UK and a company was set up in Holland as an “audacious and convincing front” for the operation, which included offices and a canteen.

National Crime Agency officers tracked one of the ambulances on June 16 after it entered the UK via Harwich and went to a car park in Smethwick.

Officers moved in when Engelsbel and another man, who was cleared of the charge, got out of the ambulance in paramedic uniforms and met with Schoon and Biljsma, who had arrived in a Mercedes.

Secret compartments behind the ambulance’s interior panels, in cupboards and under the floor contained 193 kilos of cocaine, 74 kilos of heroin, two kilos of MDMA crystal and 20,000 ecstasy tablets.

They carried a combined street value of an estimated £38 milion.

The drugs had been bound with different coloured tape which linked to a list of 20 customers found inside the car.

NCA officers produced evidence to show that the company’s ambulances were used to transport drugs into the UK at least 45 times in the 14 months before the June seizure.

The gang was caught on CCTV carrying out the ruse at Holiday Inn Express hotel in Colchester, when they arrived in a fake ambulance and Mercedes, and also at an industrial unit on a business park in the same town.